Service differentiation and fairness in IEEE 802.11 DCF

The DCF (distributed coordination function) access method of IEEE 802.11 standard cannot support QoS (quality of service) for real-time traffics. Knowing that the use of multimedia applications over WLANs is increasing, it seems essential to overcome this problem. There are many methods to enable DCF with service differentiation and QoS. The difficulty in majority of these methods is unfair bandwidth allocation among low and high priority traffics at high loads, resulting starvation in low priority traffics. In this paper we employ a scheme to enable 802.11 with service differentiation which grants dynamic priority to low priority traffics to prevent from starvation in theme especially in high load. The results of our simulations show that the starvation in proposed method is less than in DCF access method.